Light conducting elements, for example fibre optics, are a well known means of conducting light from a remote source to a desired destination. State of the art fibre optic cables allow relatively large amounts of energy to be transported through relatively small fibres that are flexible, strong, and water resistant. However inputting light energy into relatively small fibres from existing light sources can be expensive as the light sources were not necessarily originally designed for this purpose.
Most light emitting devices consist of an element for emitting light such as a filament surrounded by a vacuum or a gas or gas mixture or an arc contained in a transparent housing. Alternative types of light emitting device are a light emitting diode surrounded by a solid transparent material. Light emitted from the source radiates outward and can be reflected or concentrated by external mirrors and/or lenses in the correct direction and at the required concentration. However suitable lenses and/or mirrors have to be accurately manufactured and are relatively expensive. In use they tend to absorb the energy that is being produced. Due to manufacturing limitations the lens and/or mirror can fail to be an optimised configuration to refract/reflect the light from the source. When otherwise appropriately manufactured by existing techniques such mirrors and/or lenses fail to control the light sufficiently.
Light conducting fibres have a limited acceptance angle which means that unless the directed light is presented to the conducting element at the maximum angle or less the light is not conducted. Also every occurrence of reflection and/or lens transmission can absorb or scatter between 10 and 30% of the original light. If we add to these losses from absorbtion and transmission Further losses can be added to those of absorbtion and transmission including: those from reflector shape and size; from surface input into the fibre; and through the bulb containment housing. When all these losses are added together there is left a relatively small balance from the transmitted original light.
In order to overcome such losses many current designs utilise brighter and larger light sources. This comes at a price because apart from light such sources produce large amounts of heat which combined with bad directional control can lead to overheating of the bulb and the light conducting fibres. This leads to a requirement for an external fan or other cooling device which adds cost and bulk and an overall increase in energy required by the whole process.
These factors all limit the commercial applications for light conducting elements as the commercial cost outweighs the usefulness of the product. Alternatively the size of the device and/or its energy requirements exceed those of components available to product designers.